An organic light emitting diode is a device that emits light while holes and electrons are injected into a light emitting layer formed between electrodes through the electrodes and the injected holes and electrons generate excitons to be dissipated.
Since the organic light emitting diode has a self-emission characteristic, as compared with a liquid crystal display in the related art, the organic light emitting diode has advantages of having a small thickness, low power consumption, an excellent viewing angle, and a high response speed. Further, as compared with a plasma display panel or an inorganic EL panel display, the organic light emitting diode has advantages of having low power consumption and excellent color sense because the organic light emitting diode can be driven at a low voltage of 10 V or less. In addition, the organic light emitting diode may be prepared by using a plastic substrate having a bending characteristic.
Further, the organic light emitting diode is divided into a passive type and an active type. In the passive type, a bottom emission type in which light generated from the light emitting layer is emitted onto a substrate surface has been adopted. On the contrary, in the active type, when the bottom emission type is adopted, the organic light emitting diode is covered by a TFT, and as a result, an aperture ratio is lowered. Accordingly, in order to increase the aperture ratio, a top emission type in which light is emitted to an opposite side of the substrate has been required.
In the related art, an encapsulation method and an encapsulation structure of the organic light emitting diode having such an excellent advantage are generally to encapsulate a substrate where a light emitting element constituted by a first electrode, a second electrode, and a light emitting layer is positioned and an encapsulation cap encapsulating the substrate by using a thermosetting or photo-curable adhesive member.